Ford Repair: Ford 97 Crown Victoria, resistance measurements, diagnostic chart

Question
Hi Dennis. My car has the ECC which is giving me an error code 40 during the diagnostic-- off/floor followed by auto w/in 3 seconds.....sometimes it also displays 32 and then 40.... 1) is there someplace that could repair the control head if I removed it and sent it to them? 2) Is there a way I can defeat the ECC if I can't send it out for repair? The AC works fine when it is told by the controller to work.... Thanks Tom

Answer
Code 32 is not in the diagnostic chart. May be a false code. Ignore it for now.

Code 40 is for the ambient air temp sensor, located in front of the radiator, on the upper support. If this sensor is providing incorrect readings the EATC may think the outside air is colder than inside the vehicle therefore increasing the inside output temperature.

Here are the resistance measurements expected for that sensor:

Approximate Temperature Sensor Resistance Acceptance Range
10-20°C (50-68°F) 37K — 58K ohms
20-30°C (68-86°F) 24K—37K ohms
30-40°C (86-104°F) 16K—24K ohms

The few times I encountered this problem the sensor was faulty. Keep in mind this is an intermittent problem, so at the time you test the sensor it might check ok. I would replace it, they are not too expensive, and it may fix the concern. Otherwise more testing is needed.